Build sync engine as part of the browser build

chrome\browser\sync\util\highres_timer_linux.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // High resolution timer functions for use in Linux.
 
 #include "chrome/browser/sync/util/highres_timer.h"
 
 const uint64 MICROS_IN_MILLI = 1000L;
 const uint64 MICROS_IN_HALF_MILLI = 500L;
 const uint64 MICROS_IN_HALF_SECOND = 500000L;
 
 uint64 HighresTimer::GetElapsedMs() const {
   uint64 end_time = GetCurrentTicks();
 
   // Scale to ms and round to nearest ms - rounding is important because
   // otherwise the truncation error may accumulate e.g. in sums.
   return (uint64(end_time - start_ticks_) + MICROS_IN_HALF_MILLI) /
              MICROS_IN_MILLI;
 }
 
 uint64 HighresTimer::GetElapsedSec() const {
   uint64 end_time = GetCurrentTicks();
 
   // Scale to ms and round to nearest ms - rounding is important because
   // otherwise the truncation error may accumulate e.g. in sums.
   return (uint64(end_time - start_ticks_) + MICROS_IN_HALF_SECOND) /
               MICROS_IN_SECOND;
 }